From The Colorado Sun (Jesse Paul):
The species — previously considered extinct — is thriving in Herman Gulch, off Interstate 70, after initial stocking attempts now appear to be successful
Colorado Parks and Wildlife biologists first tried to reproduce and reintroduce the greenback cutthroat trout into a stream, not far from Interstate 70 and the Eisenhower-Johnson Tunnel, in the summer of 2016.
When they returned the next summer, the results were grim. Researchers examining the ribbon of stream that winds down Herman Gulch found that none of the thousands of inch-long swimmers that were hauled up a steep trail by volunteers and placed in the waterway had survived.
But as history has shown, there’s never really an end to the story of the ancient, threatened greenback cutthroat trout.
A few months later, in September 2017, there was a good sign.
“Lo and behold, we found some of the fish that we stocked as young-of-year in September 2016,” said Boyd Wright, a native aquatic species biologist for Colorado Parks and Wildlife’s northeast region. “We thought that it was a failed plant. We are seeing those fish, albeit in a very low percentage of what we stocked out.”
The news for greenbacks got better from there.
The creek has been stocked five times since 2016. Last year, CPW put in older fish, some of which were about 5 inches long.
“The real success story, I think, right now is with those fish we stocked last year as 1-year-olds,” Wright said. “We’ve seen on average about 35 percent survival on those. We’re really happy with that level of success. A year later, they’ve lived through a winter, they’ve lived through a runoff cycle. That’s significant.”
State wildlife officials chose the Herman Gulch stream, near a popular hiking trail, because a barrier where it spills into Clear Creek near I-70 prevents other types of trout — browns, brooks and rainbows — from sullying the genetics of the pure greenback population.
Before stocking the greenbacks, biologists remove other trout species from the creek.
CPW says the retention rate of the greenbacks in Herman Gulch is an encouraging sign for projects that the agency is working on to reintroduce the fish in other watersheds…
Greenbacks are being stocked in Dry Gulch, near Herman Gulch, and there are two more streams where CPW is building barriers — at a cost of about $250,000 — to stock the trout and keep other species out.
“Everything we know about this system tells us that it should support a population of native trout,” Wright said of Herman Gulch. “For us, we expect to have reproductively mature fish by 2019 and will best be able to detect if those fish reproduce successfully by 2020. If we see 1-year-old fish in the system in 2020, we know we had good, successful reproduction in 2019. I think 2020 is going to be a big year for this project.”
The hope is then to replicate that success elsewhere…
That passion for the greenbacks and for fishing was on display on a recent weekday morning. Several dozen volunteers from Trout Unlimited gathered with CPW officials waiting for a truck filled with thousands of tiny greenback cutthroats to arrive from Mount Shavano Fish Hatchery near Salida.
They huddled together in the chilly wind since the truck was more than an hour late. But they didn’t care about the delay.
“It’s pretty amazing to see not only the fish take hold, but the people it brings out in support of this,” Omasta said of the different people involved in hauling the trout up to Herman Gulch. “Just this past summer we had families, we had kids from middle school and a high school, walking alongside old fishermen.”
The volunteers fashioned an informal line as they waited for sloshing, 2-foot-tall, clear-plastic bags, each filled with 500 tiny greenbacks. They stuffed the bags into backpacks and headed uphill to free them into Herman Gulch.
As volunteer Brett Piché strolled up to the stream, several 5- or 6-inch greenbacks darted back and forth in the water. Piché placed his bag of fish in the water and, after a few minutes, carefully released its contents into the crystal-clear stream.
Immediately, a larger greenback swam up and gobbled a few of its smaller brethren and darted away.